Vertebrate Biology in Microgravity

Despite the sentimental appeal of human visits to the moon, people have only been transients in space. And yet, even their transient visits have started to demonstrate some curious biological paradoxes. For example, it is well known that an astronaut in space lose about 1 percent of the mineral density in their heel bone per month. But bone-forming cells do not show the same reduction when raised in tissue culture in space. The take-home message for our author is that biological processes that occur above the cellular cannot be predicted from the responses of their
cells or tissues alone. To start to answer questions—indeed, to know what questions to ask—biologists are sending animals into space to study the effects of microgravity on their growth and development. The author
discusses the surprising results of some of these experiments, which may have implications for the successful colonization of space someday in the future. People, says the author, will not have conquered the space environment until they can safely complete a life cycle in that setting.